ES2562244T3 - Prefilled syringe - Google Patents

Abstract

Prefilled syringe (A; B) comprising a barrel (1) having a front end and a base end that are open, a base end gasket (4) that is on a base end side in the barrel (1) and fluid-tight slidable in cylinder (1), a front end gasket (8) that is on a front end side in cylinder (1) and fluid-tight slidable in cylinder (1), and a nozzle part (2) provided at the front end of the cylinder (1), the nozzle part (2) comprising a front end gasket housing part (23) to house the front end gasket ( 8), and at least one liquid flow passage (21), through which a liquid medicine can pass when the front end seal (8) is housed in the front end seal housing part (23), a sectional area of a leading end of the at least one liquid flow passage (21) smaller than an area in se ction of a base end of the at least one liquid flow passage (21), characterized in that the liquid flow passage (21) is a slot provided concavely in an axial direction in a side wall of the portion of front end seal housing (23), in which the liquid flow passage (21) contains a large width portion (22) in which the width gradually increases towards a base end of the side wall.

Description

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DESCRIPTION

Prefilled syringe Technical field

The present invention relates to a prefilled syringe. More specifically, it refers to a prefilled syringe in which the inside of a cylinder is divided by a gasket, a liquid medicine or a solution and a powder medicine being stored, and which includes a nozzle part to which it is fixed. detachable

an injection needle

Related technique

A conventional preparation of a liquid medicine is such that the unsealing of the ampoules, vials, or the like in which medicines are stored separately until just before use, are opened by the use of a syringe or injection needle or similar disposable , and medications are prepared at the time of use, and then the prepared medication is used. However, this method has a complicated operation so it requires a lot of time and effort and, in addition, there is a risk that bacteria floating in the air contaminate the medicine, and a high risk of foreign objects, such as glass particles in the vial, rubber particles in the vial and the like are mixed with the medication (i.e. needle piercing infection). To solve these problems, a prefilled syringe as a combination of syringe and container has been marketed and adopted in many clinics and hospitals, to provide stability when a medicine and a liquid medicine are preserved as it is excellent for its convenience.

As a conventional prefilled syringe, a device such as that described in JP-B-62-58745 is cited. In JP-B-62-58745, as shown in Figure 1 thereof, caps 17, 12 are fluidly sealed and slidably inserted at a front end and at a base end of a tubular body 11 being both ends open, and a liquid medicament is introduced between the caps 17, 12 and can be held so safe. And, a needle holder 18, to which an injection needle 13 has been attached, is mounted in a fluid-tight manner at the front end of the tubular body 11, and a finger holding area 16 is mounted at a rear end. of the tubular body 11. An interior of the needle holder 18, on a base end side, has an inside diameter that is somewhat larger than an outside diameter of the front end cap 17, and has a front end cap housing portion having an axial length that is somewhat greater than a length of the front end cap 17. On one inner wall of the needle holder 18, one or more slot holes 22 are provided or provided that provide communication between the base end and an inner hole of the injection needle 13 of the front end, and, if the base end cap 12 is moved forward by a piston rod 15 connected to the base end cap 12 when inserted from the end rear of the tubular body 11, a liquid medicament held in the tubular body 11 between the front end cap and the base end cap 17 and 12 moves forward, and therefore a seal is released by the fact that the front end cap 17 enters the front end plug housing part, so that the liquid medicament that is in the tubular body 11 flows into the inner hole of the injection needle 13 while passing through the hole or slot holes 22 to be able to that way give yourself an injection.

The previous prefilled syringe, before the plunger rod 15 is pushed, since the liquid medicine held in the tubular body 11 is also isolated from external bacteria, is safe and, if the injection needle 13 is fixed in advance, the advantage is also beneficial, so it can be said that it is the most suitable as a prefilled syringe structure.

To all this, in the prefilled syringe having the structure described above, although a risk of needle piercing infection can be resolved, when an injection is administered by moving the front end cap 17 forward from the tubular body 11 to the interior of the front end cap housing part of the needle holder 18, it is necessary to expel in advance the air bubbles remaining in the liquid medicine that has been maintained in the tubular body 11. However, since a rear face of the end cap front 17 and a front face of the base end plug 12 are smooth faces perpendicular to an axis of the tubular body 11, there is a problem that, after the front end plug 17 enters the front end plug housing part, even Although the liquid medicine is pushed by also moving the base end cap 12 forward, the air bubbles in the tubular body 1 1 remain on the rear face of the front end cap 17 and are difficult to expel outside. In addition, since the front end cap and the base end cap 17 and 12 are made of rubber, air bubbles are likely to adhere to a peripheral face compared to glass, plastic or the like, which forms the tubular body. 11, and, also from this point of view, there is a problem that air bubbles are difficult to expel from the injection needle 13 fixed to the needle holder 18.

As a means to solve this problem, a device such as that described in JP-B-4- 46152 is cited. As shown in Figure 1 of JP-B-4-46152, the device comprises a vial

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cylindrical 11 whose front end and base end are open, a fluid-tight separation plug 23 that divides the inside of the blister 11 into a front chamber and a rear chamber, a plunger 12 placed on a base end side with respect to the separation plug 23 and sealing the interior of the blister 11, a piston rod 18 connected to a base end of the piston 12, a sealing plug 20 placed on a front end side of the separation plug 23 and which tightly closes the inside of the vial 11, a needle holder 13 in which an injection needle 15 is fluid tightly coupled with the front end of the vial 11, and a piston rod 18 provided in one part base end of the vial 11, and a projecting portion 24 protruding outward in a radial direction is formed between the separation plug 23 of the vial 11 and the sealing plug 20.

The rear chamber is formed in the vial 11 between the separation plug 23 and the plunger 12 with a solution contained therein, while the front chamber is formed in the vial 11 between the separation plug 23 and the sealing plug 20 with a powder preparation contained therein. An interior of the needle holder 13 on a base end side has an inside diameter that is somewhat larger than an outside diameter of the sealing plug 20, and has a sealing cap housing part that has an axial length that is somewhat more long than a length of the sealing plug 20. On one inner wall of the needle holder, one or more slot holes 27 are provided that provide communication between the base end and an inner hole of the injection needle 15 of the front end. If the piston 12 is moved forward by the piston rod 18 connected to the sealing plug 20 when inserted from the rear end of the vial 11, a solution contained in the vial 11 between the separation plug 23 and the piston 12 is moves forward and, if a rear end of the separation plug 23 still reaches the rear end of the protruding part 24 of the vial 11, the solution flows to the front chamber that exists in the separation plug 23 and the sealing plug 20 a through the protruding part 24, thereby dissolving the medicament. Since almost the entire front chamber is full of air and it is necessary to violently shake the device to dissolve the medication in some cases, the air bubbles adhere to a rear face of the sealing cap 20 and the discharge of the bubbles of Outward air is difficult. However, if several notches 29 are provided on a peripheral end edge of the rear face of the sealing plug 20, the discharge of the air bubbles outwards is easy (see also, for example, JP-A- 2002-177391).

However, there are problems that, since the notch 29 provided on the peripheral end edge of the rear face of the sealing plug 20 extends to a side face, the tightness of a sealing part is reduced, and that even though the sealing plug 20 moves forward during the preparation for dissolution, since a flow of liquid is created through the notch 29 just before the sealing plug is completely housed in a sealing plug housing part which exists in an interior of a base end side of the needle holder 13, some gaps are produced in a front part of the sealing cap 20 existing in an interior of the needle holder 13, so that when the piston rod 18 is pushed to the extreme when giving an injection to a patient, it does not move smoothly, thereby generating an uncomfortable sensation. In addition, there is also the problem that if the medicine and the solution are agitated in order to dissolve them, the medicine, which dissolves insufficiently, enters through the notch 29 in a concavity between seals that exist on an outer periphery of the sealing plug 20 and obstructs the concavity, and in general the notch 29 is made small in order to reduce as much as possible a residual liquid, so that it is difficult for the residual liquid to return to the front chamber. In addition, there is the problem that in a case where a distance between the common notches 29 is larger as a case in which an inner capacity of the prefilled syringe is large and therefore its inner diameter becomes large, a unless an operator manipulates such that a position of the notch 29 is positioned upward, the air bubbles adhere to the rear face of the sealing cap 20 and remain intact, so that there is a risk that the air bubbles Do not discharge abroad and you have to make changes in each manipulation.

From US 4,668,223 a pre-filled syringe is known according to the preamble of claim 1. Other syringes are known from US 4,573,972, EP 1 190 727 A2, EP 1 013 299 A1, US 2004/0097875 A1 , JP 09225032 A, WO 2005/089837 A1 or EP 1 192 966 A1.

Description of the invention

The present invention is an invention that has been carried out in view of the above circumstances, and its object is to provide a prefilled syringe in which, when an injection is administered with the prefilled syringe, it is possible to easily expel the air bubbles outside they are in the stored liquid medicine or solution prepared in a container, through the injection needle and, in a two-chamber prefilled syringe, it is possible to prevent an irregular dissolution of the liquid medicine during agitation.

After this, the present inventor devised the present invention as a result of relentlessly repeating studies in order to solve the aforementioned problems.

The present invention provides a prefilled syringe as defined in claim 1. The dependent claims define preferred or advantageous embodiments of the syringe.

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That is, the present invention is:

(1) a prefilled syringe that includes a cylinder whose front and base ends are open, an end base gasket that is on a base end side in the cylinder and that can slide fluidly in the cylinder, a front end gasket that is on a front end side in the cylinder and that can be slidably sealed to fluids in the cylinder, and a nozzle portion provided at the front end of the cylinder, wherein the part of the nozzle includes a front end joint housing part that can accommodate the front end joint, and at least one liquid flow passage which is a groove provided concavely in an axial direction in a side wall of the front end joint housing part, in which the liquid flow passage contains a large width part in which the width gradually increases towards a base end of the side wall, through which a medi liquid cament when the front end joint is housed in the front end joint housing part, and in which a sectional area of a leading end of the liquid flow passage is smaller than a sectional area of a base end;

(2) a prefilled syringe according to (1), in which there is an Intermediate gasket formed between the front end gasket in the cylinder and the base end gasket that fluidly divides an interior of the cylinder into a front chamber and a rear chamber, and a shunt protruding outward in a radial direction between the intermediate cylinder seal and the front end seal;

(3) a prefilled syringe according to (1) or (2), characterized in that a sectional area of the liquid flow passage gradually becomes smaller from the base end to the front end.

(4) a prefilled syringe according to (1) to (3), in which a concave portion or several concave portions extending in one end is provided on an outer peripheral edge of a rear end face of the front end seal. radial direction; or

(5) a prefilled syringe according to (2) to (4), in which the intermediate seal includes an annular seal portion that is in contact with an inner wall of the cylinder and that fluidly divides the syringe into the front chamber and the rear chamber, and a bypass communication passage which is a spiral groove formed in an outer wall of the intermediate joint, which communicates the front chamber with the rear chamber while cooperating with the branch.

In accordance with the present invention, when an injection is administered, it is possible to facilitate the discharge of the air bubbles in the liquid medicament that is in the prefilled syringe outside through the injection needle without damaging the preparation of the liquid medicine. or the storage characteristics of a conventional prefilled syringe. In addition, even if the inner diameter of the cylinder becomes large due to an increase in the internal capacity of the prefilled syringe, it is possible to facilitate the safe discharge of the air bubbles in the liquid medicament that is in the prefilled syringe to the outside. Despite the manipulation. In addition, in the two-chamber prefilled syringe in which the medicament and the liquid medicament are mixed and dissolved, it is possible to provide a prefilled syringe that is capable of preventing an irregular dissolution of the medicament when shaking it during preparation. . In addition, also a structure of a nozzle element is in comparison so simple as to provide only a flow passage of concave liquid on an inner wall face, so that there is no irrationality in a mold design and it can be easily manufactured.

Brief description of the drawings

Figure 1 is a cross-sectional view showing a prefilled syringe in accordance with a first embodiment of the present invention.

Fig. 2 is a longitudinal sectional view showing the positions of a front end gasket before the use of the prefilled syringe according to a first embodiment of the present invention.

Figure 3 is a longitudinal sectional view showing a state of agitation during a dissolution preparation and operating positions of the front end and intermediate joints of the prefilled syringe in accordance with a first embodiment of the present invention.

Figure 4 is a longitudinal sectional view showing a state in which air bubbles are being discharged from a front chamber during preparation for an injection and the operating positions of the front end and intermediate joints of the prefilled syringe according with a first embodiment of the present invention.

Figure 5 is a cross-sectional view showing a prefilled syringe in accordance with another embodiment of the present invention.

Embodiments of the Invention

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Next, an embodiment of the present invention is explained based on the drawings.

Figures 1 to 4 are views showing a two-chamber prefilled syringe that is a first embodiment of the present invention. Figure 1 is a cross-sectional view thereof, and Figures 2 to 4 are views in longitudinal section explaining a use of the prefilled syringe of the first embodiment. Figure 2 is a view showing a state before performing a dissolution and the position of the front end joint, Figure 3 is a view showing a state in which the prefilled syringe is being agitated for a solution and operating positions of the front end and intermediate joints, and Figure 4 is a view showing a state in which air bubbles are being discharged during preparation for injection and operating positions of the front end and intermediate joints.

Figure 5 is a cross-sectional view showing a single-chamber prefilled syringe that is a second embodiment of the present invention.

Embodiment 1

A prefilled syringe A which is a mode of application of the present invention has, among the aforementioned characteristics, the characteristics (1), (2), (3) and (5), and, moreover, it is desirable that it has the characteristic (4). Specifically, as shown in Figures 1 to 4, the prefilled syringe A is a two-chamber prefilled syringe comprising a cylinder 1 whose front end and base end are open, an intermediate gasket 6 that divides a tight seal to fluids an interior of the cylinder 1 in a front chamber and a rear chamber, an end joint of base 4 on an end side of base with respect to the intermediate joint 6 and sealing the interior of cylinder 1, a piston rod 12 connected to a base end of the base end gasket 4, a front end gasket 8 placed on a front end side with respect to the intermediate gasket 6 and sealing the inside of the cylinder 1, a nozzle element 2 that is tightly coupled to fluids with a front end of the cylinder 1 and to which a injection needle 9 is detachably attached, and a flange part 3 provided on a base end part of the cylinder 1, in which a shunt 11 protruding outward in a radial direction is formed between the intermediate seal 6 and the front end seal 8 of the cylinder 1, and the syringe comprises a structure in which the nozzle element 2 includes an end seal housing part front 23 that can accommodate the front end gasket 8, at least two liquid flow passages 21 extending in an axial direction in an inner peripheral wall, through which the liquid medicament can pass when the front end gasket 8 is has housed in the front end seal housing part 23, and a large width portion 22 of the liquid flow passage, in which a sectional area of the front end of the liquid flow passage becomes smaller than an area in section of the base end.

The nozzle element 2 is a tubular element whose front end has a nozzle 24 capable of discharging a liquid drug LD and a base end that is open and to which the cylinder 1 can be tightly attached to fluids and, in its inside, the front end joint housing part 23 is formed which is capable of accommodating the front end joint 8 mentioned below. In addition, as shown in Figure 2, on a wall inside the front end joint housing part 23, the liquid flow passage 21 is formed through which the liquid drug LD can pass when the front end joint 8 it has been housed in the front end joint housing part 23. This liquid flow passage 21 is a groove that is provided concavely in a side wall and an upper face of the front end joint housing part 23, and one of its ends is connected to an inner cavity of the nozzle 24 and the other end can communicate with the cylinder 1. Proposl / lncldentally, an axial length of the liquid flow passage 21 must be longer than an axial length of the front end seal 8 and, if it is shorter, it is impossible to discharge the liquid drug LD. In addition, the liquid flow passage 21 has a large width portion 22 in which a width increases at a base end of the side wall such that a sectional area of the front end becomes smaller than that of the end base of the side wall when viewed in the sectional area of the front end of the side wall. In addition, as shown in Figure 2, the nozzle 24 may be a male luer to which the injection needle 9 can be connected.

As the material for forming the nozzle element 2, although, for example, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, PET (polyethylene terephthalate), EVA (ethylene vinyl acetate copolymer), EVOH (copolymer of ethylene-vinyl alcohol), polyamide, polyvinylidene chloride, polyvinyl fluoride, poly-trifluorochloroethylene, polyester, nylon, mixtures thereof and laminated bodies thereof, the material is not especially limited if it is known for use as a material for medical equipment and does not interact with the medication housed in cylinder 1, and also if there is no risk of elution in the medication or the like.

Incidentally, it is quite desirable that the injection needle 9 is normally fixed to the nozzle 24. In this case, as shown in Figure 1, a needle shield 10 is mounted on the Injection needle 9. The material to form the needle guard 10 is not limited, especially if it is known to be used as a material for medical equipment and has a stiffness that avoids the risk of the injection needle 9 bending or being damaged due to a load from the Exterior.

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In a case where the Injection needle 9 is not fixed to the nozzle 24, a cap (not shown in the drawing) is used to seal the nozzle 24. As a material to form the cap, although it can be conveniently adopted an elastic material such as, for example, butyl rubber, silicone rubber, a thermoplastic elastomer and a silicone elastomer, the material is not limited especially if it is known to be used as a material for medical equipment and can seal the nozzle 24.

The cylinder 1 is a tubular element whose front end and base end are open and the flange part 3 for the application of the fingers is formed at its base end, and its front end is fluidly mounted on the element of nozzle 2. The front end of the cylinder 1 is sealed tightly to fluids by the front end gasket 8, and the base end is sealed tightly to fluids by the bottom end gasket 4. The intermediate gasket 6 is inserted in the cylinder 1, and the interior of the cylinder 1 is fluidly divided in a front chamber 7 and a rear chamber 5 by the Intermediate gasket 6. Furthermore, in a wall of the front chamber 7, the branch 11 is formed in the axial direction of the cylinder 1 in order to protrude outwardly. As material for forming cylinder 1, although, for example, glass, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, PET (polyethylene terephthalate), EVA (ethylene vinyl acetate copolymer), EVOH (copolymer of ethylene-vinyl alcohol), pollamlda, polyvinylidene chloride, polyvinyl fluoride, poly-trifluorochloroethylene, polyester, nylon, mixtures thereof and laminated bodies thereof, the material is not particularly limited if it is known for use as a material for medical equipment and does not interact with the medication housed in cylinder 1, and also if there is no risk of elution in the medication or the like.

A solution L is housed in the rear chamber 5. It is desirable that a solution such as a physiological saline solution and a glucose solution, or a liquid chemical such as a liquid medicament be housed as a solution housed in the rear chamber 5. A powder medicine M is housed in the front chamber 7. As a medicine housed in the front chamber 7, although a powder medicine that is unstable is desirable if dissolved with the liquid chemical L in the rear chamber 5, for example, lyophilized preparation of an antibiotic or the like, a form of the medicine housed in the front chamber 7 is not particularly limited and may be a liquid type medication that has to be mixed just before use.

The front end gasket 8, the base base end gasket 4 and the intermediate gasket 6 are all cylindrical elements consisting of an elastic body and have several annular ribs 41, 61, 81 formed on their side faces in a circumferential direction for contacting fluid tightly with the inner wall of the cylinder 1, and can slide in the cylinder 1. In addition, as shown in Figure 1, the ribs of the intermediate joint 6 can include an annular rib 61 formed on the end side front in the circumferential direction to contact fluidly in contact with the inner wall of the cylinder 1, a circumferential groove 62 provided concavely in the circumferential direction while contiguous to a base end side of the annular rib 61 and a passage of spiral communication 63 that communicates the circumferential groove 62 with the rear chamber 5. In this arrangement, since the joint can prevent deformation c When the gasket is inserted into a cylinder and shortened an effective sealing length that is a distance between the annular ribs 61 from most of the front end to most of the base end properly lengthening the length of the joint, it is possible to shorten a distance of movement of the intermediate seal 6, which is necessary for the rear chamber 5 and the front chamber 7 to communicate through the branch 11. In addition, an internal pressure of the front chamber 7 is raised by an advance of the intermediate seal 6 in the preparation for dissolution and therefore the inside of the front chamber 7 becomes a kind of compressed air spring and, when the solution L enters the front chamber 7 through the branch 11, the seal front end 8 moves vigorously forward and enters the front end joint housing part 23, so that there is the advantage that the medicament is prevented Liquid LD is leaking due to its great force through a needle tip 91 of the injection needle 9.

In addition, if the lengths of the annular rib 61, the circumferential groove 62, the communication passage 63 and the base end joint 4 are properly configured, it is possible to prevent the liquid drug LD from escaping outward from an end side of base of the cylinder 1 in the case of a liquid medicine whose toxicity is strong, or similar, since it is possible to avoid the risk that, when the liquid LD medicine in the prefilled syringe has been completely discharged, an annular nerve 42 that exists in the major part of the base end of the base end joint 4 moves forward beyond a base end of the branch 11. As a material for forming the joints, although an elastic material such as, for example, can be suitably adopted , butyl rubber, silicone rubber, a thermoplastic elastomer and a silicone elastomer, the material is not particularly limited if it is known to be used as equipment material doctors, and that does not generate any interaction with the medicine housed in cylinder 1.

A piston rod 12 is connected to the base end of the base end gasket 4. The piston rod 12 may be previously connected, or it may be connected at the time of use. As a connection method, coupling coupling, gear coupling and the like are mentioned. As the material for forming the piston rod 12, although a synthetic resin and the like may be mentioned, the material is not especially limited.

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60

Next, a method is explained which consists in using the prefilled syringe A of the first embodiment (Figure 1). When an injection is administered with the prefilled syringe A of the first embodiment, first, the prefilled syringe A is placed in a state in which the injection needle 91 is directed upwards. If the piston rod 12 is pushed and moved forward in an extreme front direction while supporting the flange part 3 with the fingers, the internal pressure of the rear chamber 5 is raised and, together with this, the intermediate joint 6 is also move forward. At a time when the annular rib 61 of the intermediate joint 6 has moved beyond a base end of the shunt 11, the solution L in the rear chamber 5 flows to the front chamber 7, while passing through of the communication passage 63 and the circumferential groove 62. Along with this, since the internal pressure in the front chamber 7 rises, the front end seal 8 moves forward and enters the front end seal housing portion 23 of the nozzle element 2, and thereby the seal provided by the front end gasket 8 is released, a front end face of the base end gasket 4 rests against an end base face of the intermediate gasket 6, i.e. a gas in the front chamber 7, it is discharged through the tip of the needle 91 of the injection needle outside until the gas that exists in the front chamber 7 and the complete amount of the solution L in the rear chamber 5 have moved.

Next, the prefilled syringe is agitated with an amount of force adapted to a dispersion property of the powder medicine M, thereby dissolving the powder medicine M in the liquid chemical L and producing the liquid medicine LD. At a base end of the front end joint housing part 23 a liquid surface is distorted during the stirring time, because the liquid flow passage 22 has widened, and, even if the liquid medicine passes between an inner peripheral wall of the front end joint housing part 23 and a side face of the front end joint 8 when dissolution is insufficient, immediately returns to the front chamber 7.

If the piston rod 12 is also pushed slowly and is advanced in an extreme forward direction, while the prefilled syringe A remains in the same state, a small amount of air bubbles is likely to be trapped in the LD liquid medication, which meet at the base end face of the front end seal 8 in the cylinder 1 and float, and which do not remain in the liquid flow area because a cross-sectional area of the flow passage of liquid in the side wall of the front end seal housing part 23 becomes smaller at its front end than at its base end and the bubbles are discharged to the outside before the liquid LD drug is discharged, because a Flow rate is increased towards the front end in the liquid flow passage.

Next, the needle shield 10 is removed and the needle tip 91 of the injection needle penetrates a subject part of a patient, and the piston rod 12 is pushed slowly, thereby injecting the liquid drug LD. From this state, if the piston rod 12 is also pushed hard, the leading end, the intermediate and the base end joints 4, 6 and 8 are elastically deformed, respectively, so that it is possible to inject the liquid drug LD which It is in the prefilled syringe A with no medicine left in the syringe.

A prefilled syringe B which is another embodiment of the present invention has the aforementioned characteristics, (2) and (3), and, furthermore, it is desirable that it has the characteristic (4). Specifically, as shown in Figure 5, the prefilled syringe B is a single chamber type prefilled syringe that includes a cylinder 1 whose front end and base end are open, an end base gasket 4 tightly fixed to fluidly and slidably to a base end in the cylinder 1, a piston rod 12 connected to the base end of an end base gasket 4, the front end gasket 8 fixed in a fluid tight manner and slidably to the end front in the cylinder 1, a nozzle element 2 which is fluid tightly coupled with the front end of the cylinder 1 and to which the injection needle 9 is detachably attached, and a flange part 3 which is provided in the base end portion of the cylinder 1. The prefilled syringe B comprises a structure in which the nozzle element 2 includes the front end seal housing part 23 that can accommodate the ju nta front end 8, at least two liquid flow passages 21 extending in the axial direction in the inner peripheral wall, through which the liquid medicament can pass when the front end gasket 8 is housed in the housing part of front end joint 23, and a large width portion 22 of the liquid flow passage, in which the sectional area at the front end of the liquid flow passage becomes smaller than the sectional area of the base end .

The nozzle element 2 is a tubular element whose front end has a nozzle 24 capable of discharging a liquid drug LD and a base end that is open and to which the cylinder 1 can be tightly adjusted and, in its inside, the front end joint housing part 23 is formed which is capable of accommodating the front end joint 8, mentioned below. In addition, as shown in Figure 5, in the inner wall of the front end joint housing part 23, the liquid flow passage 21 is formed through which the liquid drug LD can pass when the front end joint 8 it has been housed in the front end joint housing part 23. This liquid flow passage 21 is a groove concave provided in the side wall and the upper face of the front end joint housing part 23 and one of its ends is connected to the internal cavity of the nozzle 24 and the other end can communicate with the cylinder 1. Incidentally, the axial length of the liquid flow passage 21 must be longer than the axial length of the end joint front 8. If it is shorter, it is impossible to discharge the liquid medicine

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LD. In addition, the liquid flow passage 21 includes the large width portion 22 in which the width increases at the base end of the side wall so that a sectional area of the front end becomes smaller than that of the end of side wall base when viewed in a sectional area of the front end of the side wall. In addition, as shown in Figure 2, the nozzle 24 may be in the form of a male luer to which the injection needle 9 can be connected.

As a material for forming the nozzle element 2, although there may be mentioned, for example, polyolefin resins such as polyethylene and polypropylene, pollvlnllo chloride, PET (polylethene terephthalate), EVA (ethylene vinyl acetate copolymer), EVOH (copolymer ethylene-vinyl alcohol), polyamide, pollvlnllldene chloride, pollvlnllo fluoride, poll-trifluorochloroethylene, polyester, nylon, mixtures thereof and laminated bodies thereof, the material is not particularly limited if it is known for use as a material for medical equipment and does not interact with the medicine housed in cylinder 1, and also if there is no risk of elution of the material in the medicine or the like. By the way, the nozzle element 2 can also be a nozzle part that is formed as a single body with the cylinder 1.

By the way, it is desirable that the Injection nozzle 9 is normally fixed to the nozzle 24. In this case, as shown in Figure 1, the needle shield 10 is mounted on the Injection needle 9. As a material for forming the Needle protector 10, the material is not particularly limited if it is known for use as a material for medical equipment and has a rigidity that avoids the risk of the Injection needle bending or being damaged due to a load from the outside.

In the case where the injection needle 9 is not fixed to the nozzle 24, a cap (not shown in the drawing) is used to seal the nozzle 24. As a material to form the cap, although it can be conveniently adopted an elastic material such as, for example, butyl rubber, slllcone rubber, a thermoplastic elastomer and a silicone elastomer, the material is not limited especially if it is known to be used as a material for medical equipment and can seal the nozzle 24.

The cylinder 1 is a tubular element whose front end and base end are open and has a flange part 3 for the application of the fingers formed at its base end, and has a nozzle element 2 mounted in a fluid-tight manner in its front end The front end of the cylinder 1 is sealed tightly to fluids by the front end gasket 8, and the base end is sealed tightly to fluids by the bottom end gasket 4, thus forming a liquid medicament chamber 5. As material for forming cylinder 1, although, for example, glass, polyolefin resins such as polyethylene and polypropylene, pollvlnllo chloride, PET (polyethylene terephthalate), EVA (ethylene vinyl acetate copolymer), EVOH (ethylene copolymer - vinyl alcohol), polyamide, polyvinylidene chloride, polyvinyl fluoride, polytrifluorochloroethylene, polyester, nylon, mixtures thereof and laminated bodies thereof, the material is not particularly limited if it is known for use as a material for medical equipment and does not interact with the medicine housed in cylinder 1, and also if there is no risk of elution of the material in the medicine or the like.

By the way, the liquid LD medication is housed in the liquid medication chamber 5.

The front end gasket 8 and the base end gasket 4 are the two cylindrical elements consisting of an elastic body, have several annular ribs 41, 81 formed on their lateral faces in the circumferential direction to contact fluid tightly with the inner wall of the cylinder 1, and can slide in the cylinder 1. As a material for forming the joints, although an elastic material such as, for example, butyl rubber, silicone rubber, a thermoplastic elastomer and a The silicone elastomer, the raw material thereof is not particularly limited if it is known to be used as a material for medical equipment and that does not generate any interaction with the medicine housed in cylinder 1.

The piston rod 12 is connected to the base end of the base end gasket 4. The piston rod 12 may be previously connected, or it may be connected at the time of use. As a connection method, coupling coupling, gear coupling and the like are mentioned. As the material for forming the piston rod 12, although a synthetic resin and the like can be used, the material is not especially limited.

Next, a method is explained which consists in using the prefilled syringe B of the second embodiment (Figure 5). When an Injection is administered with the prefilled syringe B of the second embodiment, first, the prefilled syringe B is placed in a position where the injection needle 91 is directed upwards. If the piston rod 12 is pushed and moved forward in an extreme forward direction while supporting the flange part 3 with the fingers, it is likely that a small amount of air bubbles are trapped in the liquid LD drug, which are joined in the base end face of the front end gasket 8 in the cylinder 1 and float, because the liquid flow passage in the side wall of the front end gasket housing part 23 is made smaller at its front end than at its base end when viewed in a sectional area, and they do not remain and are discharged outside before the liquid LD drug because the flow rate increases.

Next, the needle shield 10 is removed and the needle tip 91 of the injection needle penetrates a subject part of a patient, and the piston rod 12 is pushed slowly, thereby injecting the liquid drug LD.

From this state, if the piston rod 12 is, in addition, pushed hard, the front end and the end joints 5 of base 4 and 8 are elastically deformed, respectively, so that it is possible to inject the liquid drug LD that is in the prefilled syringe B with no liquid medication left in the syringe.

Claims (6)

5 10 fifteen twenty 25 30 35 1. Prefilled syringe (A; B) comprising a cylinder (1) having a front end and a base end that are open, an end base gasket (4) that is on a base end side in the cylinder ( 1) and that it can slide tightly to fluids in the cylinder (1), a front end gasket (8) that is on a front end side in the cylinder (1) and that can slide tightly to fluids in the cylinder (1), and a nozzle part (2) provided at the front end of the cylinder (1), the nozzle part (2) comprising a front end seal housing part (23) for accommodating the end joint front (8), and at least one liquid flow passage (21), through which a liquid medicament can pass when the front end gasket (8) is housed in the front end gasket housing part (23), a sectional area of a leading end of the at least one liquid flow passage (21) being less than a sectional area of a base end of the at least one liquid flow passage (21), characterized by the liquid flow passage (21) is a groove concave provided in an axial direction in a side wall of the front end joint housing part (23), in which the liquid flow passage (21) contains a large width part (22) in which the width gradually increases towards a base end of the side wall. 2. Prefilled syringe (A) according to claim 1, further comprising an intermediate seal (6) located between the front end seal (8) in the cylinder (1) and the base end seal (4) and which divides in a fluid-tight manner an interior of the cylinder (1) in a front chamber (7) and a rear chamber (5), and a bypass part (11) of the cylinder (1) projecting radially outwardly and is located between the intermediate seal (6) of the cylinder (1) and the front end seal (8). 3. Prefilled syringe (A) according to claim 2, wherein the intermediate seal (6) includes an annular seal part (61) that is in contact with an inner wall of the cylinder (1) and which fluidly divides the cylinder (1) into the front chamber (7) and the rear chamber (5), and a bypass communication passage (63) comprising a spiral groove formed in an outer wall of the intermediate joint (6), which communicates the front chamber (7) with the rear chamber (5) through the bypass part (eleven). 4. Prefilled syringe (A; B) according to any of the preceding claims, characterized in that a sectional area of the at least one liquid flow passage (21) gradually becomes smaller from the base end towards the front end. 5. Prefilled syringe (A; B) according to any of the preceding claims, wherein at an outer peripheral edge of a rear end face of the front end seal (8), at least one concave portion is provided which extends radially inwards. 6. Prefilled syringe (A; B) according to any of the preceding claims, wherein said at least one liquid flow passage (21) consists of at least two liquid flow steps (21).